A man who punched four other men in the head in succession, causing one to suffer a brain bleed, has successfully argued to have his jail sentence swapped for home detention.

Shane Joseph Robertson earlier this year pleaded guilty to three charges of common assault and one of injuring with reckless disregard and was sentenced to 18 months jail.

The charges related to an incident on March 10 when the Waiuku resident and his four victims were at a party in Waiuku, a recent High Court appeal decision reads.

Shortly after midnight the group left the party and were standing at a nearby intersection when Robertson took exception to the fact they had been hanging out with his partner's younger sister.

There was a brief discussion but the victims walked away, pursued by Robertson.

Once he caught up with the group he punched them one after another in an unprovoked attack.

His first victim was struck in the face and got a bleeding nose, the second was punched in the back of the neck and the third was struck in the face but suffered no visible injuries.

The fourth man held his arms up in a non-confrontational manner and told Robertson he did not want to fight, the decision reads.

As he was backing away Robertson punched him in the face and he fell to the ground, hit his head and was knocked out.

He suffered bleeding in his brain and a serious laceration to the back of his head.

The man was still recovering from the assault several months later and was easily fatigued, scared of being alone at night, had headaches and was often anxious.

In considering Robertson's appeal, Justice Christopher Allan said the sentencing judge had acknowledged home detention may have been a better outcome for Robertson and the community, but he had to jail him because of the serious injuries suffered by his fourth victim.

Allan said while it was a "ferocious assault" it was not premeditated and Robertson could not have predicted what would have happened.

He was also concerned Robertson wouldn't get help to overcome his anger and alcohol problems in jail.

Justice Allan quashed the original sentence and imposed a nine month home detention sentence.

He said home detention was not a "soft option" and could be difficult "especially for a young man".

Justice Allan imposed conditions including that Robertson not possess, or consume alcohol or illicit drugs and that he undertake an anger management course.